The overlapping of a crater and a trench on Mars reveals a wealth of
electrical details.

Was this crater excavated by a surge in the current
that was digging the
trench?
Or did the arc that cut the crater touch down on a
high pointalong
the edge of the previously eroded rille? (Note that the crater seems
to be centered on the edge of the rille.) Note also the small
craters centered on the rim of the larger one as well as on the
edges of the trench.

The left side of the trench below the crater appears
to have a terrace cut into it, but as it nears the crater, the
terrace becomes a
shallow trench in its own right, separated from the main trench
by a dike of material. The shallow trench then stops at a craterlet
blasted into the rim of the large crater. On the opposite side of
the main trench is another shallow trench that merges into the main
trench at the point where the other shallow trench becomes a
terrace.

Note also that,
at the bottom of the image, the trench from the crater
merges with another trench at an almost exact right angle. The
terrace also turns the corner and continues along the edge of the
other trench. Significantly, the
transverse ridges on the floor of the trench also turn the
corner, indicating that they were formed by the coronal filaments
attending the primary arc that carved the channels.